[XSwiftBus] Remove unconditional socket error handling

Summary:
Socket errors are handled in libdbus conditionally. There was no need to set an error
on any kind of error code.
This caused libdbus to drop our P2P connection, since MacOS regularly raised
EAGAIN warning on the socket which seems to be expected behavior.

Reviewers: #gatekeepers

Maniphest Tasks: T513

Differential Revision: https://dev.swift-project.org/D95

src/xswiftbus/dbusdispatcher.cpp

@@ -58,7 +58,6 @@ namespace XSwiftBus
             auto *watchHandler = static_cast<WatchHandler *>(data);
 
             unsigned int flags = 0;
-            if (evutil_socket_geterror(fd) != 0) { flags |= DBUS_WATCH_ERROR; }
             if (event & EV_READ) { flags |= DBUS_WATCH_READABLE; }
             if (event & EV_WRITE) { flags |= DBUS_WATCH_WRITABLE; }
             dbus_watch_handle(watchHandler->m_watch, flags);